Method of and apparatus for evaporating and distilling



April 17, 1928. 1,666,777

J. S. FORBES METHOD OF AND APPARATUS FOR EVAPORATING AND DISTILLINGFiled July 26. 1921' Patented Apr. 17, 1928.

UNITED STATES PATENT OFFICE.

JOHN S. FORBES, OF PHILADELPHIA, PENNSYLVANIA.

METHOD OF AND APPARATUS FOR EVAPORATING AND DISTILLING.

Application filed July 26, 1921,

water, or for obtaining water in pure form' for other purposes.

I further desire to provide a novel method and apparatus characterizedas above, which shall utilize highly attenuated steam without requiringrelatively bulky or costly apparatus, and the invention more especiallycontemplates a use of the steam in such manner that the operating heatgradiant shall be relatively great, with a view to scouring stabilityand ease of operation with an avoidance of frequent and minuteadjustments or regulation.

I further desire to provide apparatus for carrying out the process aboveindicated which shall be relatively small in size and weight as well ascomparatively inexpensive.

These objects and other advantageous ends I attain as hereinafter setforth, reference being had to the accompanying drawings, in which,

Fig. 1 is a vertical section, to some extent diagrammatic, illustratingapparatus embodying my invention and in which my process may be carriedout; and

Fig. 2 is an elevation showing a modification of certain parts of theapparatus illustrated in Fig. 1.

In the above drawings 1 represents the exhaust steam pipeof a steamengine such as e a turbine, although obviously it may conduct steam fromany other source of supply. This is connected to a condenser 2 having aninlet 8 for cooling water and an outlet 4 for said water after it hastraversed the various sets of tubes 5. The water from the steamcondensed is collected in the bottom of the casing of the condenser andmay be drawn off through an opening 6.

In accordance with my invention I connect to the exhaust steam pipe 1 apipe 7 leading to a jet compressor 8 supplied with high pressure steamthrough a pipe 9 and discharging into the casing of a heater 10. Thisheater preferably contains several series of tubes 11 through whichwater or other liquid to be heated is delivered from a supply pipe 12,which for certain purposes may be connected through a branch 13 to theout Serial N0. 487.604.

let pipe 4 for the cooling water of the condenser 2. The casing of thisheater 10 is connected through a pipe 14 with the casing of thecondenser 2 and the liquid from the pipe 12, after circulating throughthe tubes 11, passes out through the discharge pipe 15 into a flashchamber 16.

The flash chamber preferably has the form of a closed, verticallyelongated tank ,in which is mounted a circular screen 17 or other devicefor finely dividing the heated water delivered from suitable openings inthe bottom of the ring-shaped extension 18 of the pipe 15. The top orupper part of the flash chamber 16 is connected through a conduit 19 toa suitable vacuum producing device such as the condenser 2 and a liquidoutlet 20 from the bottom of said chamber is connected to a suitablepump or other device for withdrawing the liquid collected therein. Asalternative to the steam operated jet compressor 8, I may, as shown inFig. 2, provide a rotary or other suitable compressor 21 for withdrawingsteam from the exhaust pipe 1 and compressing it in the casing of theheaterlO.

Under operating conditions exhaust steam is delivered to the condenser 2through the pipe 1 and cooling water or other liquid is circulatedthrough the tubes 5 of said condenser into which it passes from the pipe3 and from which it is discharged through the pipe 4-. If it be desiredto concentrate some liquid such for example as a sugar so lution, thepipe 12 would be connected to a source of such liquid and the jetcompressor 8 would be put in operation by delivering high pressure steamthereto from the pipe 9. This steam, by means of the device 8, wouldpositively draw low pressure steam from the pipe 1, increase its heat bycompression as well as supplying heat to it from the pipe 9 and deliverit into the casing of the heater 10, where it serves to heat the liquiddelivered from the pipe 12. Since the flash chamber 16 is maintained ata relatively high vacuum by suitable means such as the condenser 2, theheated liquid delivered in finely divided form from the pipe 18 over thescreen 17 is vaporized to a greater or less extent and the vapor soproduced passes into the condenser 2 while the concentrated liquid iswithdrawn through the pipe 20. v

If on the other hand it is desired to obtain a supply of distilled waterin addition to that normally provided by the condenser ill) 2, I deliverwater to the heater 10 from the outlet pipe 4 of the condenser throughthe pipes 13 and 12,..it being obvious that this water is at a highertemperature than when supplied to the condenser owing to the heatreceived when condensing the steam therein.

, This more or less heated water has its temperature further raised inthe heater 10 by the combined effect of the steam delivered from thepipe 1 to the pipe T and that due to compression as well as the steamfrom the pipe 9 delivered by the jet compressor 8 or by the mechanicalcompressor 21. The heated water delivered through the pipes 15 and 18 asbefore is vaporized to a greater or less extent within the flash chamber16 and the steam supplied by such vaporization is carried through thepipe 19 into the condenser 2, from which in the form of water it isdrawn off through the opening 6 with the water condensed from the steamby the pipe 1. The uncondensed water or other liquid falllng into thebottom of the flash chamber 16, is as be'tore; withdrawn through theoutlet 20.

livered from the pipe 1 so that its heatmay be usefully employed eitherfor distilling water or for concentrating a liquid. For this purpose thesteam jet or compressor renders the highly attenuated exhaust steamavailable foruse or puts it in a form in which its heat may be usefullyemployed without requiring bulky or heavy apparatus,-the actuating heatgradient of the steam in the heater 1() being relatively great andgiving stability and ease of operation without requiring either minuteor frequent adjustments out the quantities of steam and of the liquidflowing in the apparatus.

It is of course to be understood that for purposes of operation andregulation suitable valves are provided in the various pipes for causingor permitting operation of the system as above described.

I claim:

l. The' method which consists in continuously separating a current ofexhaust steam into two portions of which one is condensed bycoolingwater; utilizing the second portion of such steam to increase thetemperature of aportion of the water used to con-- dense the firstportion of such steam vaporizing the water so heated; and condenslngthevaporized water.

2. The method which consists in continuously'separating a current ofexhaust steam into two portions of which one is condensed by coolingwater; heating the second portion ofsuch steam and utlhzlng the heatedsteam to increase the temperature of a portion of water used to condensethe first portion of such steam; finely dividing the heated water andexposing it. 111 such form to a pressure permitting it to vaporize; andcondensing the vapor so formed.

i. The combination with an exhaust pipe and a condenser adapted toreceive and condense steam from said pipe, of means for forciblywithdrawinga portion of thesteam in said pipe passing to the condenser;a liquid heater connected to receive said withdrawn steam; means forvaporizing the heated liquid from said heater; and means for condensingthe vapor so produced.

5. The combination with an exhaust steam pipe; of a condenser adapted toreceive and condense the'e'xhaust steam from said pipe; means forforcibly withdrawing and heating a portion of the steam passing throughsaid exhaust pipe to the condenser; a liquid heater connected to receivesaid withdrawn steam; and a flash chamber connected to receive theheated liquid from said heater.

6. The combination with an exhaust steam pipe and acondenser adapted toreceive and condense the steam "from said pipe; means for forciblywithdrawing and heating a portion of the steam passing through said pipeto the condenser; a liquid heater connected to receive the withdrawn andheated steam; means for vaporizing the heated liquid from said heater;and means for condensing the vapor so produced.

7. The combination with an exhaust steam pipe and a condenser adapted toreceive and condense steam from said pipe; at liquid heater; means forforcibly withdrawing a portion of the steam passing through said exhaustpipe and for passing it to said liquid heater; means for vaporizlngliquid from said heater; and means for conducting said vapor to thesaidcondenser.

8. The combination with an exhaust steam pipe, of a condenser adapted toreceive and condense the exhaust steam from said pipe; means forforciblywithdrawing a portion of the steai'iti-passing through the pipeto the condenser; a liquid heater connected to re.-

ceive said withdrawn steam; a flash chamber connected to receive theheated liquid from $2116. heater; and a duct arranged to conduct vaporfrom said flash chamber to the condenser.

JOHN S. FORBES.

